I guess that I need one internal cable, and metalic mount "box" (size similar/same to existing SATA HDD) which contains 2 connectors (one for cable which connects mainboard and "box" (I am not sure does existing cable is good), and other connector where I should inserd M.2 PCIe SSD.

I would appreciate if someone can advice which part numbers i need to purchase in order to make feasible usage of the M.2 PCIe NVMe SSD instead of aforementioned SATAIII HDD.